180 SEVENTH REPORT. 



generator. This is a very important point and the differences are prob- 

 ably due to the fact that very little steam or moisture is given off in the 

 one method while in the other a maximum amount is liberated ; another 

 reason for this difference is that about 20% of the formaldehyde is 

 used up in the process of oxidization in the permanganate method. 



The only advantages this new method has is convenience and the avoid- 

 ance of fire, and it also does away with the necessity of transporting 

 expensive and cumbersome apparatus. It is not a rapid and thorough 

 method of disinfection, and should only be employed when its advantages 

 outweigh its disadvantages. If a generator for distilling the formalde- 

 hyde cannot be conveniently procured, and the exposure to the disin- 

 fectant can be made for a sufficient length of time to warrant thorough- 

 ness the method might be employed. 



It is quite true that any layman might employ the ^'KMnOi process/' 

 inasmuch as the method of procedure is so simple. All one requires is a 

 suitable vessel and formalin and KMnO^ in the right proportions, but 

 in cities where all disinfecting apparatus should be at hand, it is advis- 

 able to use the Novy generator. 



Pasteur Institute, U. of M. 



